Compressor controls – circuit operation

COMPRESSOR CONTROLS – CIRCUIT OPERATION

ground is applied to the Rear A/C Refrigerant Control Valve (K207) through the closed contacts of the Passenger’s Rear Fan Speed Switch (X246), BR wire, closed contacts of the Rear A/C Fan Speed Relay (K205), PG wire, UB wire, Rear A/C Refrigerant Control Valve Diode (Z228), P wire, closed contacts of the Rear A/C Evaporator Temperature Switch (X260), and the RG wire. The Rear A/C Evaporator Temperature Switch (X260) senses the temperature of the exterior fins. Should ice begin to form due to low temperature, the switch will open and the ground supply to the Rear A/C Refrigerant Control Valve (K207) will then be interrupted. The valve de-energises and refrigerant flow is interrupted. The Rear A/C Refrigerant Control Valve (K207) will also be de-energised if one or more of the following conditions occurs: The Front A/C Switch (X225) has been turned 
OFF. The Front Fan Speed Switch (X247) has been 
turned OFF. The Rear A/C switches have been turned OFF. 
The Passenger’s Rear Fan Speed Switch (X246) 
has been turned OFF. The ECM determines that compressor clutch 
operation is no longer required. Compressor Clutch (K107) operation has been 
disabled by the A/C Dual Pressure Switch (X102) or the Front A/C Evaporator Temperature Switch (X101). Compressor Clutch (K107) operation has been 
disabled by the Compressor Clutch Cut-Out Switch (X259) (300Tdi Without EDC Only).